Just a note to add perspective....I had casual conversations with two senior American instructors back in the 80's who spend some direct time with Ueshiba Morihei during the 60's when they were training in Japan.... and one of comments made (as an aside) was that none of the younger uchi deshi there at the time had any concerns with these gentlemen spending talking time alone O Sensei because none of them could really understand what he was saying anyway. The impression I got was the uchi deshi were more concerned with mat time....
Hi, I have read many accounts of uchi deshi and others. Some explain quite explicitly as to what they didn't understand and that was virtually always the spiritual.
The uchi deshi definitely were more interested in mat time as most didn't have spiritual pursuit as their primary motive. Not many do.
I've seen too many change once experiencing it to worry about any intellectual argument.